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What are the various problems and solutions of 3D printing in big data? in view of this problem, this article introduces the corresponding analysis and solutions in detail, hoping to help more partners who want to solve this problem to find a more simple and feasible way.

The 3D printer has been bought for several months, basically printing something every day, encountered a lot of problems and accumulated a lot of experience. Although desktop-level 3D printing is relatively simple and easy to use now, you still have to struggle for better print quality.

Print calibration

The calibration of the printer includes the calibration of the X, Y, Z and A, B (sprinkler) axes. The most important thing is XYAB, because they are directly related to the print size and surface quality.

Tools such as Cura and Slic3r export the GCODE format. The GCODE format describes the path in clear text. Sailfish Firmware only supports X3G files, which are binary files. Due to the slow speed of CPU used by the printer, it is relatively slow to process files and convert them into pulses, which will affect the print quality. So after using the GPX tool to convert GCODE to X3G, the position of each instruction has been converted into a pulse, and some paths can even be accelerated and decelerated. The printer's CPU can directly read the pulse and control the movement of the motor.

XY steps/mm correction

In the process of conversion, the steps per mm parameter of XY is very important, which is about how many pulses it takes to walk a millimetre. If the value is too small, it will walk less distance, resulting in a small distance. This has something to do with the structure of the machine, which involves the number of synchronous teeth and the parameters of the motor. RepRap Calculator provides a calculator for this parameter, which is very convenient.

The MBot originally used a 17-toothed gear, the same as the Replicator. Later, the 18-tooth gear was improved, which is the same as the Replicator 2. As you can see from the calculator, 88.89 steps/mm is a theoretical value, but the value 88.573186 is used in MBot and Replicator 2. Compared with 88.89, it will walk less distance, resulting in a smaller final print size. GPX developed by dcnewman provides the correct parameters, but there are still some problems so far and are not recommended.

In order to correct the error caused by 88.57, a custom configuration file can be used. Mbot.ini is the configuration file for my Mbot Cube, and when using gpx, specify gpx-c mbot.ini xxxx.gcode to convert correctly.

Of course, your printer may still be incorrect and you need to use some tools to correct it. The traditional method is to use 20mm calibration box to measure the appearance and size. However, this has a drawback, because there may be errors in the plastic extruded by the sprinkler, which will cause the corrected value to include the error of the shell. The correct measurement method is to use calibration sticks to measure the XY according to the length of different printing platforms, and then measure the distance between the two notches. This can eliminate the error of the sprinkler.

My printer uses 88.89 and prints out the correct distance.

Correction of AB axis sprinkler

The step per mm of the sprinkler has an effect on the amount of plastic extruded. When the mechanical structure remains the same, the higher the value, the more material is extruded. Too much material is called over-extrusion, which will cause the appearance size to be larger, the inner circle radius smaller, and all kinds of overlapping plastics can be seen on the top layer; if the extrusion is too small, the appearance size will become smaller, the inner circle radius will become larger, and various holes can be seen on the top layer. The correct sprinkler parameters will have a great impact on the print quality.

Calibrate your 3D printer provides a way to adjust the parameters of the sprinkler, but this article also mentions how to correct other parameters. Another commonly used method is to mark the material and then take the 10cm to measure the actual length of the walk. Of course, for printers that cannot use print run, I write a gcode file, which will automatically go to 10cm after execution, and then measure the actual length. My printer is correct, so I don't have to do too much with the sprinkler.

The hole is too small

A very common problem in printing is that the hole becomes smaller, usually about 0.5mm, and if you print this drawing, you will probably find that it cannot be plugged in. Measuring the diameter of the hole, it will be found that the hole is 0.5 mm smaller, while the diameter of the column is normal.

I printed it on MBot Cube, and it turned out like this. On the FlashForge Creator Pro, however, two can be plugged in. This problem has perplexed me for a long time and has not been solved yet. Tried to convert the same gcode file to two models of X3G to print, or the same, so you can eliminate some slicer problems. In the study of this problem, there are some articles for reference.

Calibrate your 3D printer to print parts to fit

ArcCompensation

Dimension Errors

Are you printing undersized holes? The magic of this article is that his outer and inner diameters are OK, which may have something to do with the Sublime version of Cura he uses. The one mentioned in it

Use Flow_tweak-post-processor and decrease perimeter flow rate as described above in case of holes coming out too small. Maybe it's another solution.

Although I have not used to solve this problem finally, here are some ways to improve the problem:

Change the amount of extrusion in Cura and Slic3r, there is an option to change the amount of extrusion. Even in Simplify3D, the default extrusion amount of PLA material is 90%. After testing, 90% of the extrusion volume is more appropriate, and the test block can be stuck. But the outer dimensions will also be smaller 0.2mm, the inner circle will still be smaller 0.2mm, but the cylinder will also be smaller 0.2mm, so that the two dimensions can be inserted. A smaller extrusion will cause some problems, and the setting is not recommended. Although changing the amount of extrusion can alleviate the problem of some round holes, it will also affect the quality of the top layer. To make up for this defect, the thickness of the top layer can only be set to 1mm, or 5 layers. So the top floor is basically airtight.

Sprinkler shape printing negative_space_tolerance_test.stl, my printer can only remove 2, can only say that the print quality is relatively poor. Through many comparisons, it is found that the size of the sprinkler Flat tip area (see below) will affect the tolerance, and the manufacturer is already working on improving it.

An option for XY Compensation is provided in XY Size Compensation Slic3r and is mentioned in Dimension Errors. Unlike changing the amount of extrusion, this directly compensates the sliced figure and does not cause the problem of top hole. This feature is not available in the current Cura, but it is ready to be provided in the 15.06 version of Cura development. Simplify3D is available in the latest version.

Avoid from the design to reserve some space according to the size of the hole at the design stage, but it is difficult to correct the model that others have already designed. And the correction of your printer may not be suitable for others.

A circle is not a circle

You may find that the connection at the beginning of the print garden will have some bulges, and the circle may be an ellipse. If you look at the speed and noise when printing, you will find that it may crunch when printing circles. This is because the garden will be split into several straight lines, causing each straight line to start and stop, which may cause some loss of pace or jitter at a high speed. The solution is to print the perimeter, choose a smaller speed, such as 40mm/s, so that the print quality will be very good. Looking at the GCODE of Simplify3D, it is found that it may have done different treatments for different perimeters, the speed of small arcs is slower and the print quality is very good.

The hole on the top floor

If the extrusion is normal and there are holes in the top layer, you need to set the number of layers of Top/Bottom better, generally 1mm can get a good effect. In addition, the percentage of infill is also affected, because when the infill is very low (less than 10%), it will become Bridge when printing Top, resulting in a decline in print quality.

Print wrong layer

There is an option for Accerlation in Sailfish Firmware. When this option is turned on, the firmware will generate the corresponding acceleration according to the current GCODE, so that the printer can smoothly increase speed with a certain acceleration as it slows down and increases speed. When it is turned off, it will always accelerate and decelerate with the maximum capacity of the motor as the maximum acceleration. When the motor can not accept the predetermined speed, it will cause step loss, resulting in printing error layer over time.

Printer noise

My printer has a constant rattling noise. I print so loudly at night that I can hear it from across the room when I close the door. The bearings are all oiled or the same.

After investigation, it was finally found that the plastic block in the middle was cracked. This plastic block is very important and should have a lot to do with the verticality of XY. After the change, it basically recovered.

The first layer is not adherent.

The problem of non-adhesion in the first layer is actually a headache. It is related to the following factors:

The height of the sprinkler and the first layer is generally maintained to the thickness of a piece of paper.

The amount of extrusion on the first floor. Generally speaking, it is better to choose 200% extrusion.

Generally speaking, the temperature of the first layer is better kept at 230 degrees.

The influence of materials includes the quality and color of materials. Some materials surface is rough, extruded will not adhere, and then rolled to the sprinkler, more and more rolls, resulting in printing failure. The solution includes printing a raft to reduce the speed

The answers to the various questions and solutions of 3D printing in big data are shared here. I hope the above content can be of some help to you, if you still have a lot of doubts to be solved. You can follow the industry information channel for more related knowledge.

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